Voltcraft VC-850
| Status | in progress |
|---|---|
| Counts | 6000 |
| IEC 61010-1 | CAT III (1000V) / CAT IV (600V) |
| Connectivity | RS232 / USB |
| Measurements | voltage, resistance, diode, continuity, capacitance, frequency, duty cycle, current, temperature |
| Features | autorange, hold, relative, test-lead-detection (TLD), backlight |
| Website | conrad.de |
The Voltcraft VC-850 is a 6000 counts, CAT III (1000V) / CAT IV (600V) handheld digital multimeter with RS232 or USB connectivity.
Hardware
Multimeter:
- Fortune Semiconductor FS9922-DMM4
- ...
RS232 cable:
USB cable:
Photos
Multimeter:
TODO.
RS232 cable:
See Device cables#UNI-T_UT-D02.
USB cable:
See Device cables#UNI-T_UT-D04.
Protocol
See Multimeter_ICs#Fortune_Semiconductor_FS9922-DMM4.
A short protocol description is also available from Voltcraft/Conrad.
This DMM is wired up a bit differently than "normal" for the diode mode, see below. The MEA5 to MEA1 bits are inputs of the FS9922-DMM4 chip, controlled by the position of the mode selection wheel on the DMM.
| Mode (selection wheel) | MEA5 | MEA4 | MEA3 | MEA2 | MEA1 | Mode (FS9922-DDMM4 datasheet) |
|---|---|---|---|---|---|---|
| Voltage DC / AC | 1 | 0 | 0 | 0 | 1 | DC / AC V (600.0mV ~ 6000V) |
| Capacitance | 1 | 0 | 0 | 1 | 1 | Capacitance |
| Resistance / continuity | 0 | 1 | 1 | 0 | 0 | Ohm / beeper |
| Diode | 0 | 1 | 1 | 0 | 1 | ADP (6.000) |
| Temperature (C / F) | 1 | 1 | 1 | 1 | 1 | C / F |
| Frequency / duty cycle | 1 | 0 | 1 | 0 | 0 | Hz / Duty |
| DC / AC current (µA) | 1 | 1 | 0 | 1 | 1 | DC / AC µA (600.0µA / 6000µA) |
| DC / AC current (mA) | 1 | 1 | 1 | 0 | 1 | DC / AC mA (60.00mA / 600.0mA) |
| DC / AC current (10A) | 1 | 1 | 1 | 1 | 0 | DC / AC A (6.000A / 60.00A) |
When the mode selection wheel is turned to "diode" setting, the FS9922-DMM4 chip will not be put into one of its known "diode" modes ("Diode/Beeper", "Ohm/Diode/Beeper/cap.", or "Ohm/Beeper/Diode") but instead it will use the "ADP (6.000)" setting. This will light up COM4/SEG22 on the LCD (which is a "diode" symbol on this DMM) and in the PC protocol the "z1" user-defined bit will be set (but not the "voltage" and/or "diode" bits, as one would expect). Thus, some special handling is needed in order to properly parse the diode mode setting.
See the Fortune Semiconductor FS9922-DMM4 datasheet page 11 ("Measuring Modes Select") and 12 ("ADP Input/User-Defined Symbols and Confirmation of Decimal Locations") for details.